Apple Macintosh PowerBook 1400 - Manual (Page 90)

6. Open the System Folder, then open the Preferences folder.
7. Drag the Display Preferences icon to the Trash.
8. Restart your computer without holding down the Shift key.
The computer starts up with your Extensions turned on again.
9. When the computer has finished starting up, restore any custom control
panel and network settings.
m If you hear eight tones, there may be a problem with a RAM expansion
card. If you installed a RAM expansion card in your computer, check
Appendix C to make sure the card is properly installed. If you purchased
an expansion card from a third-party manufacturer, contact the
manufacturer for help.
See also “The Computer Makes Unusual Sounds” in the section “Other
Problems While Working” later in this chapter.
The computer starts up, but the desktop doesn’t appear.
m The screen brightness may be turned down. Adjust the brightness control
(¤) and contrast control (O), located to the right of the display.
m There may be a problem with the display of the windows. Restart the
computer and hold down the Option key until the desktop icons appear.
(When the desktop appears, all windows will be closed.)
m The computer may be trying to start up using an external hard disk that
does not contain the correct system software. Shut down, disconnect the
external hard disk, and restart your computer.
m Start the computer, holding down the Shift key until you see the message
“Extensions off” in the Welcome to Macintosh box. If the computer starts
up, turn to Chapter 7 and try the steps given in the section “Checking Your
System Software Extensions.”
90 Chapter 6